This Phase I SBIR submission will provide proof-of-principle for the overall goal of developing a reliable body-worn data-acquisition system for applications that assess muscle performance and kinematics during vigorous and otherwise demanding physical activities. The system will consist of wireless sensors which combine surface electromyographic (sEMG) and accelerometer (ACC) signal detection, and a hip module for acquiring these data. Despite recent advancements in wireless sensor technology, these retain limited functionality during demanding applications, such as recording during uncontrolled movement disorders, sports activities, or activities in the work place. A design breakthrough is needed to produce a technology that does more than just provide portability, but also meets the requirements for vigorous applications. Phase I addresses this need by substantially reducing the height of the sensor and enabling it to conform to the body surface, by incorporating sensor-skin interface components with a contact geometry that provides electromechanical stability, and by introducing an overlay attachment band that secures and shields the sensor from mechanical and electrostatic disturbances when used under clothing. Each of these features represents innovations not found in comparable commercially available systems. Together they will provide a system that achieves performance metrics unattainable using current technology. The innovation will expand the ability of researchers and clinicians to investigate human movement and muscle function under these more vigorous and potentially unstable applications. The research strategy will develop sensor prototypes which meet performance criteria required for vigorous activities and evaluate them under three test scenarios which replicate clinical, sports and ergonomic use cases. These criteria are based on our experience in developing commercial sensor systems. They include electrical tests for assessing signal fidelity and mechanical tests to assess stability of the sensor on the skin. Phase I will deliver design specifications for a sEMG/ACC wireless sensor that meet or exceed performance criteria for a reliable and useful product. This phase will establish the technical merit and feasibility of the sensor technology and provide design specifications to assure a high likelihood of success for Phase II. Phase II will utilize the sensor technology to develop a pre-commercial body-worn portable data acquisition system that will be tested during vigorous use-case scenarios. PUBLIC HEALTH RELEVANCE: The development of a new non-invasive sensor system for surface electromyography and accelerometer measurement during vigorous muscle activities will enable researchers and clinicians to investigate human muscle function and movement under a substantially greater range of conditions. The proposed technology opens the doors to clinical, sports, and ergonomic applications where rapid movement of limbs and exposure to electro-mechanical disturbances preclude the use of electromyographic or accelerometer measurements; two of the most commonly relied-upon tools in these disciplines. This project will improve the ability of a) clinicians to study movement disorders, b) sports scientists to do field studies of athletes, and c) ergonomists to study work place injuries.